In 1972, William Crowther and his wife Pat were working for Bolt, Beranek and Newman in Boston, otherwise known as BBN. Will was developing the assembly language program for the original routers used in creating the ARPAnet. In their spare time the Crowthers, both avid cavers, explored and mapped portions of the Mammoth and Flint Ridge cave systems in Kentucky for the Cave Research Foundation.

Still thinking of the many beautiful sights they had seen, including caverns with colorful names like "The Hall of the Mountain King" and "Twopit Room," Will Crowther produced plotter line-drawing maps of the cave from survey data of their explorations.

Other activities Crowther enjoyed were rock climbing and a regular game of Dungeons and Dragons, a roleplaying game in which Crowther took on the persona of "Willie the Thief" among a circle of close friends.

Unfortunately, it was during this period that Crowther's marriage ended. Feeling estranged from his two daughters and wanting to be closer to them, he decided to write a program that they might enjoy: a simulation of his cave explorations that also contained elements of his fantasy roleplaying. He was intrigued by the idea of trying a computer-mediated version of the game.

He wrote a computer simulation based on the maps, for a Digital Equipment Corporation PDP-10 computer, in FORTRAN. His first version included caver jargon such as "Y2" (a common notation on cave maps denoting a secondary entrance), and many of the names of rooms in this version came from actual features in the caves Will had been exploring.

Crowther's daughters enjoyed the game, and it was passed from friend to friend during the early days of the Internet, appearing on countless computers on and off the fledgling network. Often someone would install 'Adventure' in the wee hours of the night — without mentioning it to the computer staff — and move on, resulting in a mysterious yet impressive game program seeming to appear as if by magic.

Crowther was known as a meticulous cave surveyor. He had a ASR33 Teletype set up in his living room, connected remotely to a computer at work, that he and several friends used to input cave survey data. His wife Pat wrote a program that would read this data and plot maps of the cave being surveyed.

Crowther's name and writing appears often in RFC documents produced during the earliest days of the Internet, along with many other contributors from BBN.

Crowther's exploits have been chronicled in a number of books, both for his computer and caving activities: